Making a custom .php script use the template. (2 posts)

Basically what I have been trying to do is make a custom script I made (members.php) to use the WordPress theme. I have stuck it in the themes directory and used the template functions IE

<?php get_sidebar() ?><?php get_footer() ?>

and so on.

When I run the scripts like this though it says undefined functions blah blah blah. I have tried to include all the files included in mosts scripts such as functions.php (the theme functions file), wp-includes/functions.php but it still will not work sadly. There has to be a way to do this and it is probably easy but I can't figure it out. And no I do not want to make a page template and then make a page. I have to be able to access the page through members/ and then when they want to go directly to a user they type members/username . I already have the .htaccess all ready to go but now I need to make this script sit in the wordpress theme.